class_docstr: MutualFriends dataset.
code: def __init__(self, opt, shared=None):
      self.datatype = opt["datatype"]
      build(opt)
  
      if not opt["datatype"].startswith("train"):
          raise RuntimeError("MutualFriends only has a training set.")
      opt["datafile"] = os.path.join(
          opt["datapath"], "MutualFriends", "data.json"
      )
      self.id = "mutualfriends"
      super().__init__(opt, shared)
  
file_path: ParlAI/parlai/tasks/mutualfriends/agents.py
imports: from parlai.core.teachers import DialogTeacher
  from parlai.utils.io import PathManager
  from .build import build
  import json
  import os
label_desc: Use image node_id 1 to create a new DefaultTeacher object from inherited base classes: DialogTeacher with example: obj = DefaultTeacher(opt, shared)